Modeling the Effects of Elevated Temperature and Weed Interference on Rice Grain Yield

A 3-year phytotron study was conducted in Suwon (37.27°N, 126.99°E), Korea, to evaluate and model the effects of elevated temperature on rice-weed competition. The dry weight and the number of panicles in rice were the most susceptible components to weed interference during the early growth of rice, regardless of weed species, while other yield components, including the number of grains, % ripened grain, and 1000-grain weight, were more susceptible to elevated temperature. A rectangular hyperbolic model well demonstrated that rice grain yield was affected by weed interference under elevated temperature, showing that the competitiveness of late watergrass (Echinochloa oryzicola) and water chestnut (Eleocharis kuroguwai) increased under elevated temperature conditions. Quadratic and linear models well described the effects of elevated temperature on the weed-free rice grain yield and weed competitiveness values of the rectangular hyperbolic model for the two weed species, respectively. Thus, a combined rectangular hyperbolic model incorporated with the quadratic and linear models well demonstrated the effects of elevated temperature and weed interference on rice grain yield across years. Using the combined model and estimated parameters, the rice grain yields were estimated to be 58.9, 48.5, 41.3, and 35.9% of the yields under weed-free conditions for 80 plants m−2 of late watergrass and 86.8, 64.3, 51.1, and 42.3% of the yields under weed-free conditions for 80 plants m−2 of water chestnut at 1,300, 1,500, 1,700, and 1,900°C·days of accumulated growing degree days (GDD; from transplanting to flowering, 89 days), respectively. The combined model developed in this study can provide an empirical description of both the elevated temperature and weed interference effects on rice yield and can be used for predicting rice grain yields due to weed interference under future elevated temperature conditions.

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Interactions of Nitrogen Source and Rate and Weed Removal Timing Relative to Nitrogen Content in Corn and Weeds and Corn Grain Yield

International Scholarly Research Notices ◽

10.1155/2017/8961367 ◽

2017 ◽

Vol 2017 ◽

pp. 1-8 ◽

Cited By ~ 2

Author(s):

Alexandra M. Knight ◽

Wesley J. Everman ◽

David L. Jordan ◽

Ronnie W. Heiniger ◽

T. Jot Smyth

Keyword(s):

Grain Yield ◽

Weed Management ◽

Management Strategies ◽

Field Studies ◽

Weed Species ◽

Weed Interference ◽

Coated Urea ◽

N Fertility ◽

Corn Grain ◽

Corn Grain Yield

Adequate fertility combined with effective weed management is important in maximizing corn (Zea mays L.) grain yield. Corn uptake of nitrogen (N) is dependent upon many factors including weed species and density and the rate and formulation of applied N fertilizer. Understanding interactions among corn, applied N, and weeds is important in developing management strategies. Field studies were conducted in North Carolina to compare corn and weed responses to urea ammonium nitrate (UAN), sulfur-coated urea (SCU), and composted poultry litter (CPL) when a mixture of Palmer amaranth (Amaranthus palmeri S. Wats.) and large crabgrass (Digitaria sanguinalis L.) was removed with herbicides at heights of 8 or 16 cm. These respective removal timings corresponded with 22 and 28 days after corn planting or V2 and V3 stages of growth, respectively. Differences in N content in above-ground biomass of corn were noted early in the season due to weed interference but did not translate into differences in corn grain yield. Interactions of N source and N rate were noted for corn grain yield but these factors did not interact with timing of weed control. These results underscore that timely implementation of control tactics regardless of N fertility management is important to protect corn grain yield.

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Growth and Yield Performance of Cowpea (Vigna Unguiculata (L.) Walp) as influenced by Row-Spacing and Period of Weed interference in South-West Nigeria

Journal of Agricultural Science ◽

10.5539/jas.v6n4p188 ◽

2014 ◽

Vol 6 (4) ◽

pp. 188 ◽

Cited By ~ 3

Author(s):

Joseph Adigun ◽

A. O. Osipitan ◽

Segun Toyosi Lagoke ◽

Raphael Olusegun Adeyemi ◽

Stephen Olaoluwa Afolami

Keyword(s):

Grain Yield ◽

Vigna Unguiculata ◽

Growth Parameter ◽

Crop Growth ◽

Growth And Yield ◽

Row Spacing ◽

Grain Yields ◽

Weed Interference ◽

Weed Infestation ◽

Weed Removal

Weed problem appears to be the most deleterious factor causing between 25 and 60% reduction in potential yield of cowpea. Field trials were therefore conducted to study the effect of inter-row spacing and period of weed interference on growth and yield of cowpea (Vigna unguiculata (L) Walp) at the Teaching and Research Farm of the Federal University of Agriculture, Abeokuta (07° 15'; 03° 25' E) in South Western Nigeria during the early and late wet seasons of 2009. The experiment consisted of eight main plots of weed interference which included initial weed removal for 3, 6, 9, and 12 weeks after sowing (WAS) and subsequently weed –infested until harvest as well as initial weed infestation for corresponding periods and thereafter kept weed free until harvest. There were also sub-plot treatments of three inter-row spacing of 60, 75, and 90 cm. All treatments in different combinations were laid out in a split-plot design with three replications. In both trials, the use of inter-row spacing of 60 cm resulted in significant reduction in weed growth as evident in lower weed dry matter production and subsequent higher cowpea pod and grain yields than those of 75 and 90 cm inter-row spacing. Initial weed infestation of up to 3 WAS did not have any adverse effect on crop growth and cowpea grain yields provided the weeds were subsequently removed. On the other hand, cowpea grain yield loss was not significantly averted by keeping the crop weed free for only 3 WAS without subsequent weed removal. In this study, initial weed-infestation for 6 WAS and beyond significantly depressed various crop growth parameter and cowpea grain yield compared with the crop kept weed free throughout its life cycle. In order to obtain optimum yields similar to that of the weed free cowpea field, it was required to keep the crop weed free for 6 WAS and beyond. However, frequent weeding beyond 9 weeks after sowing did not improve cowpea yield significantly and as a matter of fact it may even result in reduction of cowpea grain yield due to mechanical damage of hoe weeding. The practical implication of this finding is that early weeding starting from 3 WAS is very crucial for cowpea production while the critical period of weed removal for optimum yield in cowpea is between 3 and 9 WAS in the forest-savannah transitional zone of south Western Nigeria.

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Effect of cropping sequences on soil nitrogen levels, rice growth, and grain yields

Australian Journal of Experimental Agriculture ◽

10.1071/ea9940977 ◽

1994 ◽

Vol 34 (7) ◽

pp. 977 ◽

Cited By ~ 2

Author(s):

HG Beecher ◽

JA Thompson ◽

PE Bacon ◽

DP Heenan

Keyword(s):

Grain Yield ◽

Soil Nitrogen ◽

Subterranean Clover ◽

Rice Crop ◽

Growth And Yield ◽

Rice Grain ◽

Grain Yields ◽

Rice Growth ◽

Soil Ammonium ◽

Clover Pasture

The effect of 7 different crop and pasture sequences and cereal stubble management on soil nitrogen (N) levels and growth and grain yield of 2 subsequent rice crops was studied over 6 years (1986-92) on a Birganbigil clay loam soil at Yanco Agricultural Institute. After harvest of an initial rice crop in 1987, the following crop sequences were imposed: continuous annual rice cropping; 2 triticale crops, 2 seasons of pasture; pasture for 4 seasons; a second rice crop, 3 seasons of pasture; a second and third rice crop, 2 seasons of pasture; winter cereals; double cropped (winter-summer) on raised beds. The growth and productivity of 2 subsequent rice crops (1990-91, 1991-92) was then evaluated. Stubble retention rather than burning was practiced on half of each plot. Half of each pasture plot was sown to annual pasture (Trifolium subterraneum), while the other half was sown to perennial pasture (Trifolium repens). All plots returned to rice in 1990-91 and N rates up to 400 kg N/ka were applied. No fertiliser was applied to the 1991-92 crop. Anaerobic incubation ammonium content of soil, sampled before sowing of the 1990-91 rice crop, ranged from 28 to 85 pg/g oven-dried soil. The 1990-91 rice crop reduced soil ammonium by 30 y g/g in all sequences except continuous annual rice cropping. These differences in soil ammonium content were significantly correlated with rice growth and yield. Dry matter at panicle initiation and at physiological maturity and grain yield all increased significantly with N fertiliser application for all crop sequences. This indicates the benefit of N fertiliser, even after a 4-year pasture phase. Modelled grain yield from the unfertilised 2-year subterranean clover pasture (10.4 t/ha) was equal to that from the continuous rice sequence receiving 212 kg N/ha. Applying 320 kg N/ha to continuous rice plots produced yields similar to that of the 2-year subterranean clover pasture sequence, which received 98 kg N/ha. This indicates that the major effect on grain yield of different crop sequences could be alleviated through high N applications. Stubble management had little effect on rice growth or grain yield. Sequences with pasture phases of 2, 3, and 4 years produced similar rice grain yields. Pasture phases still had a positive effect, compared with continuous ricegrowing, on the second rice crop; however, crop growth and grain yield were about half that obtained from the unfertilised plots of the first rice crop. We conclude that continuous, high-yielding, annual ricegrowing can be maintained provided the N supply is adequate, that highly productive legume-dominant pasture phases of 2, 3, or 4 years contribute eqivalent amounts of N to succeeding rice crops, and that stubble management technique or pasture type has little effect on grain yield.

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The use of herbicides for weed control in direct wet-seeded rice (Oryza sativa L.) in rice production regions in the Republic of Macedonia

Plant Protection Science ◽

10.17221/4/2008-pps ◽

2009 ◽

Vol 45 (No. 3) ◽

pp. 113-118 ◽

Cited By ~ 11

Author(s):

Z. Pacanoski ◽

G. Glatkova

Keyword(s):

Grain Yield ◽

Weed Management ◽

Agricultural Research ◽

Oryza Sativa L ◽

Field Trials ◽

Cyperus Rotundus ◽

Effective Control ◽

Rice Grain ◽

Weed Species ◽

The Republic

Field trials were conducted in the Agricultural Research Institute for Rice, at two localities during 2005 and 2006. The objective of the study was to establish an appropriate weed management strategy for the effective control of weed flora in direct wet-seeded rice. Herbicide selectivity and influence on grain yield were also evaluated. The weed population in the trials was composed of 8 and 5 weed species in Kočani and Probi&scaron;tip locality, respectively. The most prevailing weeds in both localities were:Cyperus rotundus, Echinochloa crus-galli and Heteranthea limosa. The average weediness for both years was 456.8 weed stems per m<sup>2</sup> in Kočani locality and 589.0 weed stems per m<sup>2</sup> in Probi&scaron;tip locality. In both localities all herbicides controlled Cyperus rotundus, Echinochloa crus-galli and Heteranthera limosa excellently except Mefenacet 53 WP. All applied herbicides showed high selectivity to rice, no visual injuries were determined at any rates in any year and locality. Herbicidal treatments in both localities significantly increased rice grain yield in comparison with untreated control.

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The Effects of Single- and Multiple-Weed Interference on Soybean Yield in the Far-Eastern Region of Russia

Weed Science ◽

10.1017/wsc.2016.25 ◽

2017 ◽

Vol 65 (3) ◽

pp. 371-380 ◽

Cited By ~ 10

Author(s):

Jong-Seok Song ◽

Jin-Won Kim ◽

Ji-Hoon Im ◽

Kyu-Jong Lee ◽

Byun-Woo Lee ◽

...

Keyword(s):

Weed Management ◽

Hyperbolic Model ◽

Parameter Estimates ◽

Eastern Region ◽

Weed Species ◽

Primorsky Krai ◽

Soybean Yield ◽

Common Ragweed ◽

Common Lambsquarters ◽

Weed Interference

Lack of understanding the effects of single- and multiple-weed interference on soybean yield has led to inadequate weed management in Primorsky Krai, resulting in much lower average yield than neighboring regions. A 2 yr field experiment was conducted in a soybean field located in Bogatyrka (43.82°N, 131.6°E), Primorsky Krai, Russia, in 2013 and 2014 to investigate the effects of single and multiple interference caused by naturally established weeds on soybean yield and to model these effects. Aboveground dry weight was negatively affected the most by weed interference, followed by number of pods and seeds. Soybean yield under single-weed interference was best demonstrated by a rectangular hyperbolic model, showing that common ragweed and barnyardgrass were the most competitive weed species, followed by annual sowthistle, American sloughgrass, and common lambsquarters. In the case of multiple-weed interference, soybean yield loss was accurately described by a multivariate rectangular hyperbolic model, with total density equivalent as the independent variable. Parameter estimates indicated that weed-free soybean yields were similar in 2013 and 2014, i.e., estimated as 1.72 t and 1.75 t ha−1, respectively, and competitiveness of each weed species was not significantly different between the two years. Economic thresholds for single-weed interference were 0.74, 0.66, 1.15, 1.23, and 1.45 plants m−2for common ragweed, barnyardgrass, annual sowthistle, American sloughgrass, and common lambsquarters, respectively. The economic threshold for multiple-weed interference was 0.70 density equivalent m−2. These results, including the model, thus can be applied to a decision support system for weed management in soybean cultivation under single and multiple-weed interference in Primorsky Krai and its neighboring regions of Russia.

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Effect of Weed Removal Timing and Row Spacing on Soil Moisture in Corn (Zea mays)

Weed Technology ◽

10.1614/wt-05-098r.1 ◽

2006 ◽

Vol 20 (2) ◽

pp. 399-409 ◽

Cited By ~ 30

Author(s):

Caleb D. Dalley ◽

Mark L. Bernards ◽

James J. Kells

Keyword(s):

Soil Moisture ◽

Grain Yield ◽

Soil Depth ◽

Weed Competition ◽

Row Spacing ◽

Corn Yield ◽

Weed Species ◽

Common Lambsquarters ◽

Weed Interference ◽

Giant Foxtail

Glyphosate-resistant corn was grown in 38- and 76-cm row spacings at two locations in 2001 to examine the effect of weed competition and row spacing on soil moisture. Volumetric soil moisture was measured to a depth of 0.9 m in 18-cm increments. Glyphosate was applied when average weed canopy heights reached 5, 10, 15, 23, and 30 cm. Season-long weed interference reduced soil moisture compared with the weed free controls. At Clarksville, MI, where common lambsquarters was the dominant weed species, weed interference reduced soil moisture in the 0- to 18-cm soil depth from late June through early August and at the 54- to 72- and 72- to 90-cm depths from mid-July through the end of the season. At East Lansing, MI, where giant foxtail was the dominant weed species, weed interference reduced soil moisture at the 18- to 36-, 36- to 54-, and 54- to 72-cm soil depths from mid-June to the end of the season. Season-long weed competition reduced yields more than 90% at each location. Weeds that emerged after the 5-cm glyphosate timing reduced soil moisture and grain yield at both locations. Delaying glyphosate applications until weeds reached 23 cm or more in height reduced corn yield at both locations and soil moisture at East Lansing. Grain yields in the 10- and 15-cm glyphosate-timing treatments were equal to the weed-free corn, even though soil moisture was less during pollination and grain fill. Row spacing did not affect grain yield but did affect soil moisture. Soil moisture was greater in the 76-cm row spacing, suggesting that corn in the 38-cm row spacing may have been able to access soil moisture more effectively.

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Modeling the Effects of Nitrogen Fertilizer and Multiple Weed Interference on Soybean Yield

Agronomy ◽

10.3390/agronomy11030515 ◽

2021 ◽

Vol 11 (3) ◽

pp. 515

Author(s):

Jong-Seok Song ◽

Ji-Hoon Im ◽

Jin-Won Kim ◽

Dong-Gil Kim ◽

Yeonhwa Lim ◽

...

Keyword(s):

Weed Management ◽

Ambrosia Artemisiifolia ◽

N Fertilizer ◽

Hyperbolic Model ◽

Total Density ◽

Combined Model ◽

Soybean Yield ◽

Weed Interference ◽

Practical Tool ◽

Two Parameters

Understanding the effects of nitrogen (N) fertilizer on soybean-weed competition is essential for establishing a practical tool for N application and weed management. A two-year field experiment was conducted in a soybean field located in Bogatyrka (43.82° N, 131.6° E), Primorsky krai, Russia, to investigate the effects of N fertilizer and multiple-weed interference on soybean (Glycine max) yield and to model these effects. Soybean yield loss caused by the interference of multiple weeds including common ragweed (Ambrosia artemisiifolia), barnyard grass (Echinochloa crus-galli), and American slough grass (Beckmannia syzigachne) at different levels of N fertilizer was accurately described by a combined model incorporating inverse quadratic and exponential models into the rectangular hyperbolic model for two parameters Y0 and β, respectively. The combined model used in our study indicated that the application of N up to 36 kg N ha−1 can increase weed-free soybean yield by 2.2 Mg ha−1 but soybean yield under multiple-weed interference can sharply decrease with increasing total density equivalent, particularly at 36 kg N ha−1. These results, including the combined model, thus can support decision making for weed management under different N uses in soybean cultivation.

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Corn cultivar intercropping with arboreal legumes for weed control

Planta Daninha ◽

10.1590/s0100-83582013000300008 ◽

2013 ◽

Vol 31 (3) ◽

pp. 559-567 ◽

Cited By ~ 2

Author(s):

P.S.L. Silva ◽

P.I.B. Silva ◽

V.R. Oliveira ◽

G.L. Barros ◽

A.L. Monteiro

Keyword(s):

Survival Rate ◽

Grain Yield ◽

Weed Control ◽

Rio Grande ◽

Gliricidia Sepium ◽

Weed Species ◽

Leguminous Plants ◽

Grain Yields ◽

Yield Values ◽

Direct Sowing

Gliricidia (Gliricidia sepium) seedlings are usually beneficial to corn crops when planted between corn rows. The objective of this work was to assess the effects of corn intercropped with gliricidia and "sabiá" (Mimosa caesalpiniifolia), a species native to the Brazilian northeastern region, on weed control and corn green ear and grain yields. The experiment was carried out at Estação Experimental da Universidade Federal Rural do Semi-Árido - UFERSA (Mossoró, State of Rio Grande do Norte, Brazil). The experimental design consisted of randomized complete blocks (multifactorial design) with five replications, arranged in split-plots. The plots consisted of corn cultivars AG1051 and BM 2022; subplot treatments (six) were no-hoeing, twice-hoeing (at 20 and 40 days after sowing) and intercropping with gliricidia and "sabiá", either directly sown or transplanted, simultaneously with corn sowing. The intercropped leguminous plants were spaced 0.40 m from each other, and directly seeded or transplanted (30-day-old seedlings) in between two 1 m-spaced corn rows. Twenty three weed species were identified during the experiment. Gliricidia seedlings were superior to "sabiá" seedlings with regard to plant height and survival rate. The highest corn green ear and grain yields were found for twice-hoed subplots, while the lowest yield was found for no-hoed or intercropped subplots. However, grain yield values in intercropped treatments did not differ from grain yield values in hoed plots. In addition, marketable husked green ear mean weights did not differ between twice-hoed subplots and subplots directly seeded with gliricidia and "sabiá". Such results indicated that corn benefited from the intercropping system, but intercropping with gliricidia and "sabiá" transplanted resulted in lower benefits than with the direct sowing of those species.

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Effect of Organic Amendments on the Productivity of Rainfed Lowland Rice in the Kilombero Floodplain of Tanzania

Agronomy ◽

10.3390/agronomy10091280 ◽

2020 ◽

Vol 10 (9) ◽

pp. 1280

Author(s):

Julius Kwesiga ◽

Kristina Grotelüschen ◽

Kalimuthu Senthilkumar ◽

Daniel Neuhoff ◽

Thomas F. Döring ◽

...

Keyword(s):

Grain Yield ◽

Farmyard Manure ◽

Organic Amendments ◽

Lowland Rice ◽

Residual Effects ◽

Rice Grain ◽

Soil C ◽

Grain Yields ◽

Soil C And N ◽

C And N

Organic amendments can reportedly sustain and increase lowland rice productivity in smallholder systems. Few studies have assessed locally-available substrates in hydrologically variable floodplain environments. We investigated the effects of green and farmyard manures on rice yields, and total soil C and N in the Kilombero floodplain, Tanzania. At both the fringe and the middle positions, five treatments were applied in 2016 and 2017, comprising (1) non-amended control, (2) farmyard manure, (3) pre-rice legumes, (4) post-rice legumes and (5) a combination of green and farmyard manures. Residual treatment effects were assessed in 2018 when rice plots were uniformly non-amended. Depending on the year and the position, organic amendments increased rice grain yields by 0.7–3.1 Mg ha–1 above the non-amended control. Sole green and farmyard manure applications had similar effects on grain yield, while a combination of green and farmyard manure led to a significant increase in grain yield above both the control and sole applications of organic amendments in both years. The contribution from biological N2 fixation by legumes ranged from 4 to 61 kg N ha–1. Despite partial N balances being mostly negative, we observed positive residual effects on the yield of the non-amended rice in the third year. Such effects reached up to 4 Mg ha−1 and were largest with post-rice legumes, sole or combined with farmyard manure. Irrespective of the position in the floodplain, manures significantly increased soil C and N contents after two years, hence enhancing soil fertility and resulting in increased rice grain yields. Comparable benefits may be obtained along the hydrological gradients of other large river floodplains of the region and beyond.

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Competition dynamics of Parthenium hysterophorus in direct-seeded aerobic rice fields

Experimental Agriculture ◽

10.1017/s0014479719000292 ◽

2019 ◽

Vol 56 (2) ◽

pp. 196-203 ◽

Cited By ~ 1

Author(s):

Ali A. Bajwa ◽

Aman Ullah ◽

Muhammad Farooq ◽

Bhagirath S. Chauhan ◽

Steve Adkins

Keyword(s):

Grain Yield ◽

Rice Yield ◽

Rice Fields ◽

Parthenium Hysterophorus ◽

Rice Grain ◽

Weed Species ◽

Invasive Weed ◽

Panicle Number ◽

Direct Seeded ◽

Parthenium Weed

AbstractParthenium hysterophorus is a prolific invasive weed species, which infests many crops in over 40 countries around the world. A 2-year field study was carried out to quantify the potential impacts of this weed on direct-seeded rice. Parthenium weed was allowed to compete for 2, 4, 6 or 8 weeks after crop emergence, while full season weedy and weed-free plots were maintained as controls. Parthenium weed plants grew taller and attained more biomass as the competition duration prolonged. The yield and yield-related attributes of rice were negatively affected with increasing competition duration. The season-long competition caused the highest reductions in panicle number (28–34%), panicle length (26–27%), grains per panicle (22–23%) and grain yield (33 and 38%) of rice in both years. Weed competition for 2–8 weeks caused 5–34% and 6–33% losses in rice grain yield during both years, respectively. Importantly, Parthenium weed control after 8 weeks of competition did not improve rice yield significantly. The results suggested that Parthenium weed should be controlled in rice fields between 4 and 8 weeks after crop emergence under direct-seeded conditions to avoid over 10% yield losses.

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